1. Field of the Invention
The present invention relates to a laser beam path alignment apparatus, and in particular to a laser beam path alignment apparatus for multi-axis laser processing machines.
2. Description of the Prior Art
In the field of materials processing, the range of tasks that can now be performed by lasers is simply astounding. Consequently, it is not surprizing to see that a vast number of laser processing machines have been developed to perform extremely intricate and precise processing work.
Naturally, in order to effectively perform laser processing work, it is necessary to control very accurately the position of the laser beam at the processing location. When processing involves profiling, as most processing work does, this translates into two separate tasks: controlling the position of the focusing lens of the laser processing machine with respect to the workpiece, and centering the laser beam before it passes out through the focusing lens.
With regards to the first requirement, there are several well-known mechanical means for controlling the position of the focusing lens. Perhaps the most common way is to mount the focusing lens on the tip of a processing head made movable by mechanical arms.
Now, as for the requirement of centering the laser beam before it passes out through the focusing lens, it is necessary for the laser beam to remain perfectly aligned along each and every path it takes from the laser source to the focusing lens during the entire processing procedure. In other words, as the processing head moves along the axes of the laser processing machine, the laser beam must constantly maintain alignment along those axes.
In order to cause the laser beam to maintain alignment along the axes, in the laser processing machine, there are provided mirrors for guiding the laser beam from the laser sources to the focusing lens, each of the mirrors being provided at an end of each axis thereof. For example, in the case of a laser processing device provided with a processing head which can move freely in three dimensions, at least three reflecting mirrors are provided. Specifically, an X-axis mirror is provided on the base end of an X-axis arm, a Y-axis mirror is provided on the base end of a Y-axis arm, and a Z-axis mirror is provided on the base end of a Z-axis arm.
In addition, the mirror provided at the end of each axis can be rotated around two mutually perpendicular axes situated on the surface of the mirror so that the reflected laser beam can be projected parallel to each axis in an accurate manner.
Accordingly, by adjusting the angles of these mirrors in sequence, beginning, for example, with the X-axis, it is possible to accurately adjust the laser beam path to run parallel to each axis. By this means, even if the arms move, the focal position of the laser beam does not move relative to the processing head.
However, in a conventional device the mirrors are adjusted manually. For example, one operator observes an output beam from beside the processing head while the other operator adjusts the mirror in accordance with former operational instructions. This must be done for each mirror, one at a time, in turn.
Accordingly, the adjustment of the laser beam is an extremely tedious and time consuming operation which can only be carried out by trained experts.